O-ring face seal fluid fittings are used to connect components in fluid systems. One such O-ring face seal fluid fitting is shown in U.S. Pat. Nos. 5,490,680 and 5,564,177, the disclosures of which are incorporated herein by reference. A flat face seal fluid fitting is a fluid fitting in which a sealing surface of one of the fitting members is a generally flat surface or face disposed in a plane that is generally perpendicular to the central or longitudinal axis of the fitting and a seal carried by the other fitting member engages the flat face. In this type of fluid fitting, the seal may be a conventional elastomeric O-ring that is retained in a groove in the other fitting member and that provides a fluid seal when the other fitting member is connected to the first mentioned fitting member. The elastomer material for the O-ring is selected in a known manner.
U.S. Pat. No. 5,681,064, the disclosure of which is incorporated herein by reference, is directed to fluid fittings with metal seals. These fluid fittings include conventional metal seals retained on one of the fitting members by an external retainer and providing a fluid seal when the fitting members are connected together. The metal material for the seal is selected in a known manner. In some applications, the material for the metal seal is stainless steel plated with silver.